In this study, the previously noted limitations of high-performance passenger tire tread were overcome by adding rough-surface carbon nanotubes and soybean oil to a high-loading silica-based elastomer composite. The results of the practical tire test demonstrated improved wet braking, dry braking, snow traction, and rolling resistance in comparison with the unmodified silica-based composite. Moreover, the wear resistance was enhanced by greater than 20% while commercially acceptable levels of the other properties were maintained, thereby minimizing the trade-off. The wet traction and dry stability of the tires were enhanced by the inclusion of carbon nanotubes, while the improved snow traction and wear resistance were increased by the soybean oil. Therefore, this carbon nanotube/soybean oil-based composite may represent a useful and practical means of improving high-loading silica-based elastomer composites.